bulma (file, components): fix color fo icons: icons have no color specified anymore for a while, and use the color of parent elements. As they are often used in a `<a>` element (to work without javascript), they are often using a link color. This commit change a few icons to use a dark color instead.

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    <span class="has-text-info is-size-7">{% trans %}new messages{% endtrans %}</span>
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